ALAS2-2026-3865

References: CVE-2026-50185  CVE-2026-53583  CVE-2026-53584  CVE-2026-53585  CVE-2026-53586  CVE-2026-53587 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in constant-time and not be rewritten as branches by the compiler. From 0.1.1 until 0.5.4, the aarch64 implementations of Cmov and CmovEq in cmov/src/backends/aarch64.rs assume high bits are zero-extended when loading values smaller than a register, so set high bits such as [8..] in a Cmov selector or [16..] of self or other in the u16 and i16 CmovEq implementations can cause left.cmovz(&right, condition) to produce incorrect output. This issue is fixed in version 0.5.4. (CVE-2026-50185)

libgit2 Inverted IP SubjectAltName Comparison in OpenSSL Backend ( vuln_1_1_1 ) (CVE-2026-53583)

libgit2 Submodule path traversal (CVE-2026-53584)

Unbounded Memory Allocation via Delta Object Result-Size Header (CVE-2026-53585)

libgit2's builtin HTTP transport follows offsite redirects for the initial smart HTTP request by default. If the redirected server then returns 401 Unauthorized, libgit2 asks the application credential callback for credentials using the original remote URL, not the redirected URL. The returned credential is then attached to the next request to the redirected host as an Authorization header. (CVE-2026-53586)

libgit2 version 1.9.4 and below is vulnerable to a heap out-of-bounds read in set_data() in src/libgit2/transports/smart_pkt.c.

The vulnerable code uses a fixed-size strncmp (smart_pkt.c:239) against the unvalidated capability buffer of a smart-protocol pkt-line. When the bytes following the pkt-line in the contiguous receive buffer happen to continue with "ct-format=", the comparison spuriously matches, advancing format_str past the pkt-line boundary. The following memchr(format_str, ' ', len - (format_str - line)) (smart_pkt.c:246) then underflows its size_t size argument to ~SIZE_MAX and walks the heap looking for a space byte. An unauthenticated remote attacker who controls (or man-in-the-middles) a Git server reached over HTTP/HTTPS/SSH/git:// can trigger this on the FIRST ref-pkt of the refs advertisement, before any capability negotiation has taken place. The OOB walk causes a process crash (SIGSEGV) when memchr enters an unmapped page, and -- on heap layouts where memchr finds a stray space byte before crashing -- can additionally drive the git_error_set("...'%.*s'", format_len, format_str) formatter to copy a large window of heap memory into the error string. (CVE-2026-53587)

Issue Correction:
Run yum update rust or yum update --advisory ALAS2-2026-3865 to update your system.

New Packages:

aarch64:
    rust-1.97.0-2.amzn2.aarch64
    rust-std-static-1.97.0-2.amzn2.aarch64
    rust-doc-1.97.0-2.amzn2.aarch64
    cargo-1.97.0-2.amzn2.aarch64
    rustfmt-1.97.0-2.amzn2.aarch64
    rust-analyzer-1.97.0-2.amzn2.aarch64
    clippy-1.97.0-2.amzn2.aarch64

noarch:
    rust-debugger-common-1.97.0-2.amzn2.noarch
    rust-gdb-1.97.0-2.amzn2.noarch
    rust-src-1.97.0-2.amzn2.noarch
    rust-toolset-srpm-macros-1.97.0-2.amzn2.noarch
    rust-toolset-1.97.0-2.amzn2.noarch

src:
    rust-1.97.0-2.amzn2.src

x86_64:
    rust-1.97.0-2.amzn2.x86_64
    rust-std-static-1.97.0-2.amzn2.x86_64
    rust-doc-1.97.0-2.amzn2.x86_64
    cargo-1.97.0-2.amzn2.x86_64
    rustfmt-1.97.0-2.amzn2.x86_64
    rust-analyzer-1.97.0-2.amzn2.x86_64
    clippy-1.97.0-2.amzn2.x86_64